Support for continuation of a long-term study directed at the isolation, characterization and structural elucidation of new and potentially useful cancer chemotherapeutic drugs from terrestrial plants has been summarized. Research will continue to be devoted to plant species yielding extracts with a very significant confirmed level of activity in the National Cancer Institute's murine P-388 lymphocytic leukemia screening program. Once each plant problem has been solved or discontinued (due to lost activity) another high priority plant will be selected for study. Plants continue to be excellent sources of new drugs for cancer treatment. Discovery of useful cancer chemotherapeutic drugs for human cancer treatment continues to be exceedingly important and most necessary research objective so the overall grant program is expected to be quite productive and provide very significant results.